Lewis Gun

The Lewis gun (or Lewis automatic machine gun or Lewis automatic rifle) is a World War I-era light machine gun of American design that was widely used by the British Empire. It was first used in combat in World War I, and continued in service with a number of armed forces through to the end of the Korean War. It is visually distinctive because of its wide tubular cooling shroud around the barrel and its top-mounted drum-pan magazine. It was commonly used as an aircraft machine gun, almost always with the cooling shroud removed, during both world wars.

Lewis Gun
Class Manportable
Type Machine Guns
Manufacturer Savage Arms
Production Period 1913 - 1942
Origin United States of America
Country Name Origin Year
United States of America 1913
Country Name Operational Year Retirement Year
Korea 1950 1953 View
United States of America 1914 1918 View
Vietnam 1946 1954 View
Vietnam 1955 1975 View
ManufacturerName Production From Production To Quantity
Savage Arms 1913 1942 View

The Lewis gun was gas operated. A portion of the expanding propellant gas was tapped off from the barrel, driving a piston to the rear against a spring. The piston was fitted with a vertical post at its rear which rode in a helical cam track in the bolt, rotating it at the end of its travel nearest the breech. This allowed the three locking lugs at the rear of the bolt to engage in recesses in the gun's body to lock it into place. The post also carried a fixed firing pin, which protruded through an aperture in the front of the bolt, firing the next round at the foremost part of the piston's travel.

The gun was designed with an aluminium barrel-shroud which caused the muzzle blast to draw air over the barrel and cool it. There is some discussion over whether the shroud was really necessary—in the Second World War many old aircraft guns which did not have the tubing were issued to anti-aircraft units of the British Home Guard and to British airfields. Other weapons were used on vehicle mounts in the western desert and did not suffer without the tube. They were found to function properly without it, leading to the suggestion that Lewis had insisted on the cooling arrangement largely to show that his design was different from Maclean's earlier prototypes. Only the Royal Navy retained the tube on their deck-mounted AA-configuration Lewis guns.

World War I: The first use of the Lewis in the War was by Belgium, in August and September 1914, when the small number available were fitted to a handful of touring and armoured cars and used in a few sorties against German patrols and troop columns. It is stated that as a consequence the Germans nicknamed the Lewis "The Belgian Rattlesnake"., but contemporary German references have not been found. The Lewis was not in service with the regular Belgian Army.

Aircraft use: The Lewis gun has the distinction of being the first machine gun fired from an aeroplane; on 7 June 1912 Captain Charles Chandler of the US Army fired a prototype Lewis gun from the foot-bar of a Wright Model B Flyer.

World War II: At the start of World War II, the Lewis was the Royal Navy's standard close-range air defence weapon. It could be found on major warships, armed trawlers and defensively equipped merchant ships. It was often used in twin mountings and a quadruple mount was developed for motor torpedo boats. British submarines generally carried two guns on single mounts. Although it was gradually replaced by the Oerlikon 20 mm cannon, new corvettes were still being fitted with twin Lewises as late as 1942. Lewis guns were also carried by the Royal Air Force's air-sea rescue launches.

Type Light machine gun
Place of origin United States United Kingdom
Service history
In service 1914–1953
Used by Australia, Belgium, Canada, Chile, Republic of China, Colombia, Czechoslovakia, Estonia, Finland, France, Democratic Republic of Georgia, German Empire, Nazi Germany, Honduras, Ireland, Israel, Italy, Empire of Japan, Mexico, Netherlands, New Zealand, Nicaragua, Norway, Philippines, Poland, Portugal, Russian Empire, Soviet Union, Sri Lanka, United Kingdom & British Empire, United States, Kingdom of Yugoslavia, Latvia
Wars World War I

Emu War

Banana Wars

Irish War of Independence

Irish Civil War

Latvian War of Independence

World War II

Korean War

Malayan Emergency

1948 Arab–Israeli War

The Troubles

Yugoslav Wars

and other conflicts
Production history
Designer Samuel McClean

Colonel Isaac Newton Lewis

The Birmingham Small Arms Company Limited
Designed 1911
Manufacturer The Birmingham Small Arms Company Limited or BSA

Savage Arms Co.
Produced 1913–1942
Variants Mks I–V

Aircraft Pattern

Anti-Aircraft configuration

Light Infantry Pattern

Savage M1917
Weight 28 pounds (13 kg)
Length 50.5 inches (1,280 mm)
Barrel length 26.5 inches (670 mm)
Width 4.5 inches (110 mm)
Cartridge .303 British

.30-06 Springfield

7.92×57mm Mauser
Action Gas-operated
Rate of fire 500–600 rounds/min
Muzzle velocity 2,440 feet per second (740 m/s)
Effective firing range 880 yards (800 m)
Maximum firing range 3,500 yards (3,200 m)
Feed system 47- or 97-round pan magazine

30-round detachable Bren magazines
Sights Blade and tangent leaf

End notes